Use Linux... You need to put it into fastboot by holding up and power until it vibrates. The screen will then turn white, plug it into your computer (possibly do this first) and type "fastboot devices" to check if it's connected. Then, after you've been on Sony's website to find your unlock...
Haha yeah fair. Haven't checked what the differences are yet. Anyone know? I've ported a few ROMs for my old Moto G (falcon), which now has many nougat builds available for it! Just wish more development was done for Sonys.
Update
I find it extremely unlikely there'll be an update anytime soon for nougat, and especially O. I'm thinking about porting a rom to my f3111. If someone can lead me to an O rom for a similar device, that'd be helpful!